Bones. Charcoal. Ash. Blood. Feces. Food waste. Pottery shards. Before I began my journey into permaculture and regenerative ecology, if you asked me why someone would gather and bury these things together, I would have guessed at some kind of disgusting voodoo magic ritual. But for those initiated into the alchemy of composting and soil generation, this is actually a recipe for the most nutrient-dense, hyper-fertile soil on the planet — terra preta, or “black earth”.